1. Field of the Invention
This invention relates to magnetic image recording systems and more particularly to transfer printing systems for printing latent images magnetically onto a transfer medium moving past a magnetic print head array which prints onto a medium for receiving a permanent printed image.
In another aspect, this invention relates to coincident current wiring arrays for operating a plurality of elements having a binary operating characteristic by application of binary, ternary or higher order signals to a set of bit lines and a set of word lines.
2. Background Art
Three types of recording modes are possible for magnetic printing. Vertical recording, in which the magnetization is perpendicular to the plane of the medium has been pursued as in "Magnetic Printer Using Perpendicular Recording", J. J. P. Eltgen and J. G. Magnenet, IEEE Trans. on Mag., MAG-16, 961 (1980). However the method requires the use of special media and involves recording heads which are difficult to fabricate for high resolution printing applications. An alternative is transverse recording, in which the magnetization lies within the plane of the medium but transverse to its direction of motion, as described in "Transverse Recording Head for Magnetic Printing", A. E. Berkowitz, J. A. Lahut, and J. M. Wang, U.S. Pat. No. 4,097,871. Although this type of recording can be achieved with a relatively simple head array structure, the implementations result in a pattern of recorded spots with unrecorded spaces between them. Thus, the quality of the print is not as high as it would be if the entire area of the medium could be magnetized in a pattern of stripes of alternating polarities. With longitudinal recording, in which the medium is magnetized in the plane but along the direction of motion, any type of pattern can be generated.
U.S. Pat. No. 3,890,623 of Schmid for "Magnetic Document Encoder Having Multiple Staggered Styli" describes an arrangement in which "styli are staggered along a row oblique to the transport path of the medium such that each stylus is a different distance from the reference line. Portions of the medium lying along a line normal to the transport path will thus pass adjacent each stylus at a different time. Electronic delay circuits are provided to accordingly selectively delay the application of the energization pulses to given styli." Later it is stated "The physical size of the styli and the associated electromagnetic coils surrounding each stylus needed to generate an intense localized magnetic field to magnetize such permanent magnet materials can be accomodated in a structure in which the styli are diagonally positioned relative to the transport path. The styli within the second group . . . are, therefore staggered along the transport path to avoid magnetic interference and space limitations. Such positioning of the styli together with selective energization of the styli in time spaced relationship to the movement of the medium along the transport path provides for closely spaced magnetized area with the distance perpendicular to the transport path . . . between the first and last styli . . . respectively, permitting the alphameric characters to be formed having the height of a standard alphameric font, i.e. 0.100 inches (2.54 mm)." The stylus assembly is employed to encode a medium such as a source document carrying magnetic particles, which document is carried under the styli by means of an endless belt. The magnetized medium "is useful as a master source document in which the magnetized locations represent encoded information, which information is readily magnetically transferred to a transfer sheet." No mention of magnetic printers is made.
U.S. Pat. No. 4,072,957 of Kokaji et al for "Non-impact Printing System with Magnetic Recording Apparatus and Method" describes recording a magnetic latent image with an array of scanning recording heads on a magnetic recording medium. The medium is a drum covered with a thin magnetic film. Magnetic toner is applied to the drum by forming the latent image on the drum from the operation of the recording heads. In FIG. 8 a staggered array of heads in a v formation is shown. The heads are operated by a delay circuit which compensates for the space between the heads so that the magnetic record pattern on the drum is formed in a line. Reference is made to such a circuit with "a method for recording characters, letter and marks on the drum using multiple heads" in Japanese Pat. No. 50-23567.
U.S. Pat. No. 4,176,362 of Nelson for "High Density Magnetic Image Recording Head" shows an array of magnetic recording heads aligned in a straight line to record data on magnetic tape which transfers the data onto a magnetic drum in a printer using magnetic toner. Then terminals to the heads are shown in a staggered array" so that the entire arrangement of elements including the common interconnect regions and the staggered and relatively wide terminals can be accomodated in a head of moderate size." The heads are aligned and are not staggered. There is a wiring scheme, which does not relate to the instant wiring system particularly.
U.S. Pat. No. 4,257,051 of Lindsay et al for "Apparatus and Method for Driving a Magnetic Print Head" describes a coincident current winding arrangement for driving magnetic print heads in a special sequence to minimize spurious printing caused by undesirable concentrations of magnetic flux. For each head both a word winding and a digit winding has to be energized to actuate it, in a coincident current actuation scheme modified by breaking the digit windings into groupings of nonadjacent heads so that each grouping can be energized separately and successively to minimize spurious magnetic flux distribuions.
In accordance with this invention, a class of recording head structures is provided which is suitable for high resolution magnetic printing using longitudinal recording. Also a novel method of coincident current wiring is introduced which leads to a reduction in the number of control lines required for addressing arrays of recording heads and which is applicable to a wide class of transducer or memory element arrays. The application of this method to the proposed type of longitudinal recording array results in extremely simple and compact wiring patterns.
An array of magnetic recording heads is provided for producing spots in a single row, but they are staggered along the y axis (relative to the x axis along the horizontal row) in order to reduce the magnetic interaction between adjacent heads. The activation times of the heads need to be staggered in order to cause a straight line to be printed. This is used in a magnetic transfer printer. The magnetically printed image is later transferred from a magnetic transfer medium on which the print is made to a paper on which toner is fixed, as in magnetic transfer printing. Preferably, the staggering of the heads is provided with parallel staggered arrays of heads forming a subset of heads. Preferably the subset has an additional staggering of the first head in each row of the staggered subset in the y direction. The double staggering of the heads in the parallel arrays in a subset of heads is provided for the purpose of optimizing separation of the heads and to minimize the head alignment problem when fabricating the heads with the horizontal alignment of the wiring transverse with respect to the arrays being straight and permitting a substantial lateral shift in position of heads along the wiring.
The magnetic elements are activated by a modified half select technique wherein there are clusters of elements. These clusters comprise a multiplicity of elements sharing identical wires. The wires are would about each of the elements in the cluster but some of them are wound with one polarity and some with the other polarity so that each element has a unique set of polarity characteristics so any one of the elements in a cluster can be activated by currents of the proper polarity in the wires of the proper polarity in the wires common to that cluster.
Thus an array of N wires and a cluster of K transducers is provided, where N and K are integers greater than one, each of the transducers having N wires as inputs, each of the transducers being responsive by producing an output upon reception from the wires of a unique binary combination of values on the N wires, with all of the remainder of the K transducers not being responsive to the unique binary combination.
In accordance with this invention, an arrangement of magnetic recording heads for recording a magnetic line of data, the heads are in a staggered arrangement in order to provide greater separation between heads for a given data density along the line of data. The arrangement is separated into a plurality of parallel segments at a predetermined periodicity to form a group of heads. Preferably, a plurality of parallel arrays extends at an angle to the line of data to be printed; and the arrays are staggered relative to each other. Further for a group of heads, a single energizing line comprising a bit line is coupled to each of the heads, and a plurality of word lines are connected to subgroups of heads in the group. A pair of heads is connected to a set of word and bit lines with the sense of the magnetic fields of the set of word and bit lines being relatively reversed through the pair of heads whereby operation of the bit line and the word line will depend upon the sense of current polarity in the lines. Preferably, the heads in such a group of heads are arranged with parallel arrays of heads contained within a shape in the form of a parallelogram tilted within a 90.degree. sector with respect to the line of data to be printed with one array extending at a small acute angle to a perpendicular with respect to the line with the adjacent heads in the array printing adjacent points on the line and with the parallel array to the one line having the lowest head in the array staggered along a perpendicular line, with respect to the lowest head in the first array in the group. Preferably, the lowest head in each array and the highest head in each array define the upper and lower ends of the parallelogram extending at a small acute angle above the printing line. It is desirable that the word lines are parallel straight lines extending directly through the gaps in the heads to which the word lines are coupled with a plurality of groups of arrays of heads being coupled to each of the word lines in like manner.
In an arrangement of a plurality of magnetic heads formed in a staggered array, the improvement comprising the heads being formed in a plurality of groups of parallel arrays with the gaps in the heads in adjacent arrays being aligned in a periodically staggered arrangement with a word line being coupled to heads along a transverse line on a periodically selective basis and all of the heads in a group being coupled to a single bit line with the sense of current for a given head being reversed in the bit line for the other head coupled to the same word line.
A structure carrying a plurality of magnetic recording heads in a staggered array arrangement wherein the array is formed of a plurality of parallel arrays of heads staggered along a given line of the arrays with the parallel arrays being staggered relative to the line being recorded wherein the heads in a given array are formed in a strip of magnetic material deposited into a diagonal parallel slot in a substrate with a plurality of strips inserted into a plurality of slots with transverse diagonal cuts through the strips cut in parallel across the strip to form slots for magnetic recording gaps. The said are cut by means of a horizontal cut, a plurality of cuts between the heads being cut at a small acute angle extending down into the substrate thereby removing superfluous magnetic strip material from the strips to define separate magnetic heads from the strips.
In an arrangement of a plurality of bistable devices having at least two actuation lines comprising bit and word lines for actuating selected ones of the device, the improvement comprising grouping the devices into clusters and actuating the devices with a common set of lines by reversing the sense of actuation current in each of the lines connected to the devices in the cluster.
An array of magnetic heads is arranged in a staggered set of arrays adapted to produce data which is transferred by a scanning surface interacting with the heads to produce a straight line of data, with parallel staggered arrays of heads forming a subset of heads, with staggering of the columns of arrays along the y axis in order to maximize the separation distance between the magnetic heads to minimize the interaction between the heads.
In an array of N wires and a cluster of K transducers, where N and K are integers greater than one, each of the transducers having N wires as inputs, each of the transducers being responsive by producing an output upon reception from the wires of a unique binary combination of values on the N wires, with all of the remainder of the transducers not being responsive to the unique binary combination.
A set of magnetic elements activated by a modified half-select technique wherein the elements are divided into clusters.
The clusters comprise a plurality of elements sharing identical wires, with the wires shared by the elements being applied to the elements with differing polarity permutations for each element, whereby each element is supplied a unique set of input signals so that any one of the plurality of elements in a cluster can be activated by signals of the proper polarity in the proper combination while all of the remaining elements in the cluster will not be activated for the proper combination for the one of the plurality of elements.